new leaves with blackened tips falling off Begonia
I'm a newbie to plant care, indoors and out and would love some advice for my faltering spotted angel wing Begonias that I brought indoors at the end of last summer. I have been keeping them alive in Brooklyn, NY, in an enclosed room with CFL light bulbs, humidifier and temp. around 60-72 degrees. I have been using a moisture sensor to make sure not to over water. They have been doing ok until recently the new leaves are turning black and falling off before they barely unfurl? Some mature leaves have holes and long slice-like scars and dead dry brown tips?
I've been scouring Google "image search" for a picture that matches my plants' symptoms but can't quite find the same decaying look. The new leaves, that mature beyond the unfurling stage, eventually develop a soggy translucent spot on its edge that can expand to consume almost a 1/4 of the entire leaf until it drops off. I have uploaded some images of my beloved but sad Begonias in hopes someone can make suggestions on what I should do?
Any input to help me identify what's causing these symptoms will be so appreciated and contribute to my greening thumb's education? I figure I shouldn't start my seedlings for spring planting in this same grow room until I can confirm its not a fungus etc.?
Thank You for any insight-Spring Hopes Eternal!